serine-type endopeptidase activity obsolete endopeptidase Clp activity true caseinolytic protease activity endopeptidase Clp activity molecular_function ClpP This term was made obsolete because it represents a gene product. Clp protease GO:0008462 ATP-dependent Clp protease protease Ti activity endopeptidase Ti activity OBSOLETE. Catalysis of the hydrolysis of proteins to small peptides in the presence of ATP and magnesium. Alpha-casein is the usual test substrate. In the absence of ATP, only oligopeptides shorter than five residues are cleaved, for example, succinyl-Leu-Tyr-NHMec which is cleaved at the Tyr-NHMec bond, and Leu-Tyr-Leu-Tyr-Trp which is cleaved at the second Leu-Typ bond (cleavage of the Tyr-Leu and Tyr-Trp bonds also occurs).